| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F |
| Average First Frost Date: | Sep. 21 - Sep. 30 |
| Average Last Frost Date: | May 21 - May 31 |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate |
| Ecoregion: | 25l - Front Range Fans |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 80127 - Littleton, CO | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 15 | 18 | 24 | 32 | 41 | 50 | 56 | 55 | 45 | 34 | 23 | 15 | 34 |
| Avg Max Temp (°F) | 44 | 48 | 54 | 60 | 69 | 81 | 86 | 84 | 76 | 65 | 52 | 45 | 64 |
| Avg Precip (In.) | .53 | .56 | 1.55 | 2.36 | 2.8 | 1.91 | 1.73 | 1.9 | 1.33 | 1.11 | 1.17 | .72 | 17.66 |